Switch to Syn Oil/Gear oil in my diesel...

[Ashmck]

I have a 6.9 Navistar IDI, with LOTS of gunk every time I change the oil.

I want to switch to Syn oil and Gear oil, But I dont want to just drain the Dyno oil out then poor in syn oil with all that regular oil gunk still in there.

There are oil "Flushes" out there that basicly thin the oil out while you idle it a few mins before change... but is this enough?

Or sould I just drain, put in syn oil and wait till my next change so the syn oil can clean all the dyno gunk out?

[SD26]

A motor flush would probably be a good idea before changing. Generally, the flushes are only ran for several minutes, and I believe that's because they are sometimes made of kerosene and it will strip stuck on stuff from surfaces, including the areas that need a lubricating boundary layer. Hence, it only takes five minutes or so.

What oil were you using that it's so loaded up or is it just not getting warm enough?

[Ashmck]

I only ever put Rotella T 15W40 in it

But my dad tops it off with cheap 10W30 from Autozone when It gets a little low.

He works for me and uses the Van alot of the time.


As far as getting warm enough I would think it does, because the Van is loaded down with 1500+lbs of Carpet cleaning equipment and Water.

and it was just as gunky in the summer.

[SD26]

Maybe it's an incompatability issue with the additive packages between the Rotella and the cheaper oil?

Rotella is a very good oil. It's used by a lot of manufacturers as their branded oil, especially for diesel applications where the oil goes through more orifices and all. That would create foam in a non diesel oil, an oil that doesn't have an API "C" rating.

Maybe you just need proper refills?

Back to temperature...

My 7.3PSD in my van, which carries a 2000# box and 4000# trailer which then gets loaded up, doesn't get very warm at all. Seems like all the Navistar/International/PSD engines have cooling systems that are just over built. Might want to look at the cooling system once just to check to make sure that it's not cooling too much. This next summer, I'm going to actually block off some of the radiator to generate more heat as the engine responds to that well.

[Ashmck]

Originally Posted by SD26

Maybe it's an incompatability issue with the additive packages between the Rotella and the cheaper oil?

Rotella is a very good oil. It's used by a lot of manufacturers as their branded oil, especially for diesel applications where the oil goes through more orifices and all. That would create foam in a non diesel oil, an oil that doesn't have an API "C" rating.

Maybe you just need proper refills?

Back to temperature...

My 7.3PSD in my van, which carries a 2000# box and 4000# trailer which then gets loaded up, doesn't get very warm at all. Seems like all the Navistar/International/PSD engines have cooling systems that are just over built. Might want to look at the cooling system once just to check to make sure that it's not cooling too much. This next summer, I'm going to actually block off some of the radiator to generate more heat as the engine responds to that well.

You have a good point on the temp,

I actually took out the HUGE radiator and installed one from a gas motor that was about 45% smaller, maybe I need to block it a little lol.

Thanks for your help.

[SD26]

Hey, no problem. Hope it gives you some ideas. You can help me the next time around.

[JanGeo]

Yeah that gunk may be the cheep oil breaking down - especially if it is not diesel service type oil. Also running hot make oil break down faster - a lot faster!

[Erdrick]

As a general rule, don't let dad's near your crankcase. They love to put in the wrong oil. I about blew a gasket (quite literally, perhaps) when my dad put the wrong oil in my TDI. For some reason, dads refuse to believe that oil is a very critical part of protecting your engine, and that different oils are that -- DIFFERENT!

Diesel oil changes should be pretty black and dirty though. That tells you that the oil is doing its job correctly! Chunks are another story. I personally would pony up the $15 odd to get a used oil analysis. That should tell you a lot more than anyone on some website about FE could...

[smay665949]

I am using Amsoil in all of my wives VW TDI and my Ford Powerstroke with excellent results. My Ford starts quicker and idles much smoother than it did with Rotella. I am also running Amsoil in my tranny and gearboxes on my ford. With Amsoil in the engine and drivetrain I have gained about 10% in fuel economy bringing my milage from 17-19 MPG.